Acts 12:5

3And because he saw it pleased the Jews, he proceeded further to take Peter also. (Then were the days of unleavened bread.)

4And when he had apprehended him, he put him in prison, and delivered him to four quaternions of soldiers to keep him; intending after Easter to bring him forth to the people.

5Peter therefore was kept in prison: but prayer was made without ceasing of the church unto God for him.

6And when Herod would have brought him forth, the same night Peter was sleeping between two soldiers, bound with two chains: and the keepers before the door kept the prison.

7And, behold, the angel of the Lord came upon him, and a light shined in the prison: and he smote Peter on the side, and raised him up, saying, Arise up quickly. And his chains fell off from his hands.